Arc-extinguishing device



P. MACGAHAN.

ARC EXTINGUISHING DEVICE.

APPuc/mou FILED AUG/i0. 1916.

1 ,308,365 Patented July 1, 1919.

gV/ITNESSES I, INVENTOR Pdlj/ M46 Gdhdl? w ATTORNEY Copending applicatio UNITED ,STATESTPATENT OFFICE.

PAUL MAoG-AHA N, OF PITTSBURGH, PENNSYLVANIA, ASSIGNOR T0 WESTINGHOUSE ELECTRIC AND'MANUFACTURING COMPANY, A CORPORATION OF PENNSYLVANIA.

, ARC-EXTINGUISHING DEVICE.

Specification of Letters Patent.

Patented Jui i, 1919.

Q ,ippljcationfiledAugustIO, 1916. Serial No. 114,162.

To all whom'z't may concern; j ,1 Y

' Be it known that I, PAUHMACGAHAN', a citizeniof-the United States, and a resident of Pittsburghin thecOunty'ofAlIeghcny and State of .en'nsy'lvania, have invented a new and usefulflmprovenient in Arc-Extinguishin "Devices, of the following is aspecication.

M "nvent1onrelate s to electrical systems of istributionzand"particularly to apparatiis I for i'shin that 'o'c'cur such syste auteur 'sturbin" the operation of "theja'ppa'ratus connecte thereto.

' one object at my i ven ion ism provide a device of the ,above"indioatedcliaracter that shall alternatelydopen" and fclo's'e agcirciiit interrupter to i so reducefthe voltage of .the' 'cir-i' cuit'pthat the are. will be extinguished. iifiith out causing the apparatus connected to the Another object of my invention is to provide a device of the above indicated character that .shall' have a I 'time-limitoverload relay lfoi preclu'ding the automatic reclosing of theiiiterru' ter' after metre-has persisted for such p're etermined p'xeriodsof'time' as shall be determined by t e timesetting of the overload re1ayl""': f*' f I" n' vSerial No. 83,786,

filed-March 13, ieieby-ir; E. Ricketts and assignedto the Westinghouse Electric and Manufacturingllomp'anydisclosesa dev ce for alternately opening and closing a circuit interrupter in accordance w1th the difference in potential on therespective sides of 1 the interrupter and means for pr clud ing the closingof the interrupter a er. the archas existe of time.

In my invention, I provide an overload relay for tripping the interrupter, a n0- volta e relay for quickly reclosing it and a timeimit overload relay for prec uding the operation of the reclosingmeans after the arc has existed for a predetermined period of time.

The" single figure of the accompanying drawing is a diagrammatlc view o a distributing system-that is "provided with an arc-extinguishing means embodying my invention. 1 A generator lsupplies energy to conductors2 and '3 of a distributing system or circuit'4 that isprovided with an interrupter for, a predetermined period.

5 which is adapted-to be tripped when an overload or'an arcing ground occurs upon the circuit 4 and to be immediately reclosed in order that the load which is connected to the circuit will not fall out of synchronism. That is, if the circuit interrupter 5 is tripped-,-the voltage upon the load end of the circuit 4 is reduced substantially to zero, and, if the'overload is caused by an arcing ground,thearc willbe extinguished because of'the lack of voltage to maintain it.'

' The circuit interrupter '5 is provided with a'tripping electromagnet 6' and a closing electromagnet 7. A series transformers is ogeratively connected to the circuit 4 and is a 'apted =tofenergize the windings 9 and 10 of overload relays 11- and 12; The overload rela'y 11 is adapted to operate substantially instantaneously,fupon the occurrence of an overload-,--for the purpose of completing a circuit from one conductor- 13 of'a circuit 14:, comprising'a source 15"ofelectromotive force, throughthe tripping electromagnet 6 to the other conductor 16. of the circuit 14:. Thus, when an overload-occurs-upon the circuit 4:, the interrupter 5 will be tripped.

A 'no-voltage relay'17 is adapted to be connected across the conductors 2 and 3 on the load side of the interrupter 5 and comprises a winding 18, a movable core member 19, a bridging contact member '20 and stationary contact members 21. One of the stationary contact members 21 is connected to the conductor 13 and the other stationary contact member 21 is connected to one of the stationary contact members 22 of a relay 23. The other stationary contact member 22 of the .relay 23 is operatively connected to the movable contact member 24 of a switch 25 and to thestationary contact member 26 of a time-limit relay 27. The other stationary contact member 26 of the relay 27 is connected to one terminal of its winding 28, the other terminal of which is connected to one terminal'of the electromagnet 7 The other terminal of the electromagnet 7 is connected to the conductor 16 of the circuit 14. Thus, when the circuit interrupter 5 is tripped, the voltage of the load end of-the circuit 4 Wlll drop substantially to Zero, and themovable core member 19 of the relay 17 will move downwardly to cause its bridging contact member 20 to engage its stationary contact members 21, thereby completing the clrcult through the electromaghet 7 for the purpbse of reclosing the interrupter 5-.

The time-limit overload relay 12 comprises the winding 10, a dash pot or other suitable time-element device 29, a movable bridging contact member 30, and stationary contact members 31. One of the stationary contact members 31 is' operative'ly connected to the conductor 13 and the'other stationary contact member 31 is operative ly connected to one terminal ofthew n i ng 32 of therelay 23, the other terminal of which is operatively connected tothe conductor 16 of'the circuit 14.

The relay 23. is provided with a;latchin ggized if the overload has existedlupon thev circuit 4 for a predeterminedv period of time. The dash pot 29 of the relay'12 is,.of;course, so set that the circuit interrupterfi maybe' tripped and reclosed a predeterminednumber of times before the'contact member 30 engages the contact members31, .Gonsequently, the ti'mesetting of the relay 1271s dependent upon the time required to extinguish an arc by successively, reducing the voltage thereacro'ss. v

The relay 27 is provided for the purpose of precluding thecontinued energization of the winding of the electromagnet 7 should the voltage of the generator I fail, for any reason. That is, if the voltage of the generator 1 fails, the movable contact member 20 of the relay 17 will engage its stationary contact members 21 and thus cause current to traverse the electromagnet 7 until the voltage is again restored to the circuit 4. The relay 27 is provided with a dash pot 36 which is so set that, if current traverses its winding 28 for a predetermined relatively short interval of time, its movable contact member 37 will be disen'gaged from its stationary contact members 26 and thus open .the circuit'of the electromagnet. The relay 27 may be provided with a latch 39 for holding it in its "open position, after it has 0perated, until it is manually reset.

The movable contact member 24 of the switch 25 is adapted to engage a stationary contact member 38 that is operatively connected to the conductor 13 for the purpose of so "energizing the electromagnet 7 that the circuit interrupter 5 may be non-automatically reclo'sed, under any condition.

When an overload traverses the circuit 4, the relay 11 will operate to trip the interis en g e at i sv rupee? 5" throu gh the elctroimtgiiet 6 and, at the same time, the relay 12 will start to operate. When the circuit interrupter 5 opens, the voltage on the load end of the circuit 4 will so decrease as to cause the core member 19 of-the relay 17 to move downwardly. This will cause the electromagnet 7 to reclose the interrupter 5. 'If the arc thatcauses the overload upon the circuit 4 has been extinguished by reason of the reducing of the voltage, nothing further will occur. However, if the are persists, the re lay 11 will again cause the interrupter to be tripped and, similarly, the relay 17 will again cause the interrupter to be reclosed. After the tripping and reclosing operations have occurred a number of times, dependent upon the time-setting of the relay 12, the relay 22 will operate to thus prevent the automatic reclosing of the interrupter.

. Ifthe overloadfis caused by a permanent ground, the am will an: be" eiitiii'guishei'no matter how gma nytiijnes the. interrupter is opened Hence, it has been found that, if the ground ig, iiet cieareaanr' the interrupter,.has opened and closed a i" 1a, tively times, isu'se ess to eontinuethe; operation, and, under {such ed ums the m n 33 is adapted so new the relay 23 th at tthe a l ltebe automatically reclose manuallyreleased.

L d n t. .1mm men to p ticular arrangement il ustrated, as itinay be var sly m di ied. e t spirit and scope of thefmvention, as set forth in the ppn a e I claim as my invention": I

1. In an electric circuit, the combination with a circuit- 'interrupter and mm-Sim: opening and closing the same, or an ove'r load relay for "controlling u ezfimning of the interrupter when anfl overload occurs upon the c1rcuit,a no-voltagerelay'for controlling thfifteclosing of the interrupter whentlre o tage of the circuit is substantially/zero, and a time-limit overload relay for" opening the circuit of the reclosing means if the overload persists for a predetermined period of time.

d until the latch 33 is 2. In a system of distribution, the mate means for rendering the closing means inctl 'ective if the overload persists for a predetermined period of time.

4.. In a system of distribution, the combination with a circuit interrupter, of an overload relay for tripping the interrupter when an overload traverses the system, a no-voltage relay for closing thelinterrupter when the voltage on the system'drops to a predetermined value, and a time-element overload relay for precluding the closing of the interrupter if the overload persists for a predetermined period of time.

5. In a system of distribution, the C0111 hination with a circuit interrupter and means for successively opening and closing the same when an overload traverses the system, of a time-element overload relay for precluding the reolosing of the interrupter after the overload has existed for a predetgrinined period of time.

6. In a system of distribution, the combination with a circuit interrupter and means for successively opening and closing the interrupter when an overload traverses the system, of retarded overload-responsive means for precluding the reelosing of the interrupter after the overload has existed for a predetermined period of time.

7. In a system of distribution, the combination with a circuit interrupter and means "for successively opening and closing the interrupter when an overload traverses the system, of overload-responsive means for preventing the energization of the closing means of the circuit interrupter after the overload has existed for a predetermined period of time.

In testimony whereof, I have hereunto I subscribed my name this 31st day of July, 1915.

PAUL MACGAHAN. 

